In the past, jarring devices have proved useful for the purpose of cleaning the heating surfaces of pipe coils, particularly where such heating surfaces of pipe coils have been exposed to gases which are heavily particle-laden. For example, they have been used, among other things, in the waste-heat boilers of calcining furnaces. By means of such jarring devices, which may be operated at predetermined time intervals, adherent particles are loosened and shed from the outer surface by the jarring of the pipe coils against each other. Known jarring devices of this type may be regulated as to jarring frequency by monitoring the temperature of the effluent gas, since it will rise as the pipes become particle covered and; therefore, less efficient in heat transfer capability. In this connection reference is made to U.S. Pat. No. 3,721,217. With such jarring devices, however, there is a danger that the periodic forces arising from the motion of the pipe coil masses may transfer, by way of their bearing elements, onto the body of the boiler and its supporting structures. Therefore, the bearing elements must be designed and/or dimensioned to withstand such extra dynamic loads. In addition, the transfer of periodic alternating forces from the masses in motion may produce troublesome oscillations, (i.e., resonance) in supporting structures, scaffolding and/or buildings, which might, under certain circumstances, totally or partially destroy, or at least damage, portions of the installation. Alternatively, the period of jarring may be varied to reduce such adverse effects, but this is undesirable because this makes the frequency of jarring, and therefore the cleaning effectiveness and periods, depend on considerations not necessarily, or even usually, related to the factors which are relevant to the rate of particle accumulation.
Therefore, an object of this invention is to provide a means for the cleaning of the heating surfaces of pipe coils in such a way as to minimize or minimize or prevent the transfer of forces to the body of the boiler from the pipe coil masses as they move.